When determining whether a chemical reaction has taken place, you observe and look for several indicators. Which would be
considered an indication that a chemical reaction or chemical change has taken place?
Solid melts.
Heat is given off.
Substance dissolves
Substance changes shape.

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.

Amap that uses a range of colors and shading to represent the elevation, depth, or landscape of specific features on earth is a/an map.

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?